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Method of Mixture.

When the body and the water are in thermal  equilibrium, the

final temperature T of the mixture is taken.    Then, the heat

lost by the body divides itself between the  water and the
casing, so

Heat lost by body           = Heat gained by water & casing,

weight x sp. ht. x fall of temp.   = weights x sp. hts. x rise of temp.
ws (/ - T)               -        (wl s} -f wfy) (T - /!>,

where w wl and w^ are the weights in Ibs., and s sl and J2 the
specific heats of the body, the water, and the casing respectively :
jj being unity. The value w% s% is known as the * water equivalent'
of the vessel. The first temperature of the water is // while f is
that of the body after steaming; and the changes are shewn
graphically at A, Fig. 598. Inserting known values, that of

s may be found, the following table being obtained by this and
other methods:


Water at 39 'i
	...   I '00
	Wrought iron
	...    ^113

Water at 212
	... 1-013
	Steel ......
	...    -116

Ice at       32
	...    -504
	...    -095

Steam at 212*
	...    -48
	Coal ......
	...    '24

	...    '033
	Air    ...    ...
	...    -238

Cast iron
	...    -13
	Hydrogen ...
	... 3"44